The worldwide market for mass timber buildings and structures continues to expand and many are rising in Japan, often combining modern construction techniques with traditional Japanese joinery.    The latest is the Obayashi Port Plus building in Yokohama, the port city that serves Tokyo.    Completed last year, Port Plus is a fully wooden-framed, fire-resistant high rise composed mainly of 540 wooden rigid cross-joints that are 9.2ft-wide by 13ft-tall.    “We believe that the utilization of forest resources will lead to the realization of a ...